Effect of ultrasound pre-treatment on drying kinetics and quality properties of jerusalem artichoke

-- Jerusalem artichoke (Helianthus tuberosus L.) is primarily used as a biomass for ethanol production. It is also utilized for human consumption as a healthy snack by having good nutritional value and inulin content. In this study, ultrasound pre-treatment (USPT) was selected to minimize drying defects and 5, 10 and 15 min. treatments were applied before hot air drying at 60 °C and 80 °C. The effect of pre-treatment on drying performances and properties as color, total phenolic content and total antioxidant were investigated. Effective diffusion coefficient values ​​ranged from 1.72 × 10-8 m2/min to 2.94 × 10-8 to m2/min, and it was observed that the effective moisture diffusion coefficient was higher in the samples where ultrasound was applied compared to the control sample. L * value 72.72 ± 2.71 was found highest at samples that were 5 minutes ultrasound treated and dried at 60 ° C for 60 minutes. The highest antioxidant and phenolic content in the drying process at 60 °C was determined in the samples where ultrasound was applied for 15 minutes. Consequently, more conserved quality in shorter drying time with desired end product moisture content can be achieved by the application of USPT.